Lt. Rich Hill said the gunman entered the store at 101 Vintage Way in the Vintage Oaks shopping center around 7:45 p.m.
He ordered the 18 and 21-year-old women to give him all the money from the register then ordered them to get down on the floor. The suspect escaped with about $320, Hill said. There were no injuries.
The suspect is about 6 feet tall and weighs between 170 to 180 pounds. He was wearing a white rag over his face, a white T-shirt, blue jeans and black gloves.